With the most modern technology it is often a lot like magic - a brief typed, or spoken command, or one selected with a mouse click and magic happens. Few people have any idea of what is happening to make the magic: Even fewer have this knowledge if you exclude those who were alive and active when the magic was being developed. It is no good though for me (or us*) to get smug about our deep undeby leadinglights - General
Like Roberts_Clif I used a SWTPC; but in my case it was a 6809 running Flex - later replaced by Uni-Flex then a Unix knock off called Quix - all on 96 Kilobytes (not Megabytes or Gigabytes) of RAM. This was in the very early 1980s. Back in those days an elderly (elderlier than I am now) technician used to re-filament and rebuild radio valves from the 1920 and 1930s as a hobby. When asked why heby leadinglights - General
Quotethe_digital_dentist .................. Is your extruder having some sort of problem? I am not having any problems yet, but if I use a wirewound resistor rated at 3 Watts in air and ask it to dissipate up to 32 watts I have to be sure that the heat will get away - or I will have problems. Early trials showed that it will, but now the resistor body size has changed and most thermal compoundsby leadinglights - General
I have found 3 of the original 5 dummy hotend blocks that I used some years ago to do the failure test. I think I will try a repeat of the earlier test with different compounds - with and without copper shims to fill the gap. Machining new blocks to fit the resistors would be a pain - and wouldn't guarantee that the next batch would have the same diameter. Mikeby leadinglights - General
The hotend is my own design but uses a vitreous enamel wirewound resistor instead of a heater cartridge. The reason for this is that I was an early adopter of heater cartridges but they let me down badly - I have never had a WW resistor fail. Part of the problem here is that this design uses a very small resistor which is over-run to the wazoo and beyond: The element wire temperature gets to 420by leadinglights - General
Has anybody used pyrolytic graphite based heatsink compounds on their hot-end heaters? Arctic MX-4 is an example of such a compound but they offer no data on maximum temperatures. The significance of this question is that I have used such a compound that I acquired when it was banned by a health and safety officer due to the lack of a material hazards datasheet. This compound had a thermal conduby leadinglights - General
When I looked for PAT9125 the first thing I came across was a PR (pull request) on Github from the Prusa team . Some interesting stuff there. Between the Prusa and Duet laser sensors and the simpler wheel sensors, I think this field is pretty well covered so I will use my efforts elsewhere. Mikeby leadinglights - General
@ECJ I am intrigued by the "Prusa" sensor that you linked to at as I can't understand out how it detects movement in what must be a very short path length. I am moderately sure that I can detect movement including direction and speed by monitoring the movement of a texture on the surface of the filament. My problem is that any practical way I can find to do that needs a decent optical path, notby leadinglights - General
QuoteThingiverseAfter scheduled maintenance yesterday, Thingiverse is experiencing issues with search. Our engineers are investigating now. Please try again later. The engineers have obviously tried Ctrl-Alt-Del dozens of times and even tried switching it off and on again I think it is just not a priority - and maybe never will be again Mikeby leadinglights - General
QuoteECJ ......................................................... As for the filament presence sensors, I believe that the most useful are those that are also capable of detecting movement, because if something occurs that obstructs the movement, the simplest sensors become useless. I believe that the work of creating a new sensor using capacitance detection would only be justified if it could aby leadinglights - General
If a member of this community comes up with an idea that transforms 3D printing for the better and then successfully keeps it from the capitalists of the western world and the cloners of the Orient then it would never be made and will not transform 3D printing. The RepRap world may have been different in the past, but how many now make their own 3D printer? How many make their own extruder? Doesby leadinglights - General
@ECJ I think you are right on all counts although there is still a possible place where the capacitative sensor could be used. Humidity will vary between the outer layers of a roll and the inside. The layers most exposed to the most recent humidity will reflect that. Filament quality when I made my first printer in 2011 was pretty awful but I don't think I have seen a thickness problem in severaby leadinglights - General
QuoteECJ ............................................. I believe that moisture absorbed by the material will affect the dielectric constant more than the composition itself. .............................................. Although there seem to be several strikes against a capacitive sensor for measuring how much plastic is being fed, there may be occasions where it does not matter: One of theby leadinglights - General
An interesting design, I will watch to see how it goes. A passing thought - It looks like the filament is stored on the right-hand side of the printer with access through a door: Having a heated chamber where the filament and printed part are held at a high temperature during printing does not mean that rolls of filament will also take the same temperature. It may be necessary to have some passiby leadinglights - General
A possible problem with capacitative sensors is that the dielectric constant of PLA, ABS and other plastics may vary widely. Ways could be found around this,such as having a cell with a sample of the feedstock of a known diameter; but there would remain a quality problem as it would not account for the dielectric constant varying along the length of the roll. From Google search for "Dielectric pby leadinglights - General
I like the idea of the capacitive sensor although I would try it as a stack of electrode rings with the filament going through them - I may try this out as I have a bridge that goes down to the sub-picofarad region. As promised, a drawing of the filament thingy with a reference chamber and port. The measurement is made on the measurement sensor - thinner filament lets more air out and hence a weby leadinglights - General
One of the branches that this thread has evolved into concerns a device that I was once interested in. Instead of following this branch on this thread, I will append some thoughts on the earlier thread As far as the ethics committee goes though, I hereby swear and aver that I shall return to the true geek path of enlightenment and abjure from patents, copyrights, and other tools of oppressionby leadinglights - General
On another thread, there has been a little discussion of this idea with an emphasis on the generation of low frequencies. Although it has been several years, I think there is no particular advantage to lower frequencies but that the linearity became very poor much above a few hundred hertz. There is obviously a 'sweet spot' where acceptable linearity is obtained - my guess from earlier work is thby leadinglights - General
Ah! but then I can't see how a method and apparatus for the measurement of the cross-sectional area of feedstock for fused fabrication printers could be used for ends antithetical to the continued survival of the human race. This leaves me without a moral reason to continue work on it or to desist from such endeavors - perhaps I have dodged a bullet there. Mikeby leadinglights - General
Hi Viktor, I more or less lost interest when I found that purchased filament had be come very predicatbly round with a consistent diameter - In the past variability had pretty much been a given. If you are interested in the approach I used there is a bit more here I still have a long-throw 40mm diameter woofer which I intended to use as a driver with a piezo as a sensor, it is awaiting the rby leadinglights - General
It is true that patents are not always effective and can even be harmful, but almost everything else is the same: Masks are of limited effectiveness against viruses, fertilizer won't guarantee a good crop, a seatbelt is not always effective in a car crash and democratic elections won't stop you getting a bad government. The main thing about patents is that if you want money from a bank, a brotherby leadinglights - General
A very interesting video. It makes me want to video/document my own humble efforts. Mikeby leadinglights - Developers
QuoteVDX ......................................................................... -- too, to prevent companies from using/stealing the ideas ... Ditto, but now it seems a lot like shouting your ideas into the void - not even an echo can be heard. Mikeby leadinglights - General
A simple question: How do the members of this forum feel about patents? My own take: In the past, when the community was arguably contributing as much or more to the FFF knowledge base than the commercial world it seemed unreasonable to take knowledge from the free interplay of ideas on the forum and fence it off as your own. As the energy has declined it now seems that any new idea you have isby leadinglights - General
Thank you both. I had been looking at a schematic of the Arduino Mega2560 which was missing the far right-hand side. The missing bit shows that PE0 and PE1 (D0 and D1) are connected to M8TXD and M8RXD on the USB MCU. EDIT: I have managed to move some ports about and have avoided having devices connected to multiple plugs so all is well. Mikeby leadinglights - RAMPS Electronics
I am not sure what you mean by "used", but there is no other physical connection tracing back to the MCU - details below. Can you give any hints on how to free them in the firmware? While I could find other pins, I would like to avoid having wires going to different connectors - AUX4 is already used for the manual controls/LCD and AUX3 is fully occupied with an SD reader, AUX2 feeds two piezo prby leadinglights - RAMPS Electronics
I would like to use the AUX-1 connector on a RAMPS1.4 to power a device for which I will need two logic level outputs and one logic input. D57 on this connector works as expected with M42 P57 S255 setting the output high and M42 P57 S0 clearing this pin - D58 also works as expected but D0 and D1 both seem to be stuck on outputs at 5V. Firmware is Repetier 0.92.9. Any thoughts on how to use thesby leadinglights - RAMPS Electronics
The latest touch probe (photograph below) is sensitive enough to detect the difference between being tapped with a clean metal bar and one with a fingerprint on the surface. I had not expected to see this kind of sensitivity, but it seems like it may be useful for finding problems like badly seated print surfaces etc. I will put some details in this forum once I have got it running in conjunctby leadinglights - Tech-Talk
I tend to be a bit 'old school' when faced with problems like this. Logging the step and direction inputs to the stepper motor driver(s) with a logic analyzer will get pretty close to giving you a true picture of the position. I have used a 'Saleae' logic analyzer for this purpose on X, Y, and Z motors simultaneously. Genuine Saleae analyzers are about £400 although clones are available at aboutby leadinglights - General
Just a brief note about squaring up extrusions. In the distant past, before 'T' slot extrusion was popular, my father had to make up an aluminium frame from 1" square aluminium bar. Hd did this with a hacksaw, some files, a Moore and Wright square, a test flat and some machinists blue - and most importantly, a scraper made from a modified wood chisel. This last because it is just about impossibleby leadinglights - Mechanics